1. Field of Invention
This invention pertains to a structure for heating a sauna wherein a stack of bricks with high heat retention properties is selectively shifted between an oven and a sauna for heating the latter.
2. Description of the Prior Art
Heated spas and saunas have been used for many years for different therapeutic purposes. Various methods have been used to heat such rooms or other areas with a spa. One common method presently used is to indirectly heat a sauna by first convectionally elevating the temperature of a movable heat source to a high temperature in an oven, transporting the heated source to the room, and allowing the source to radiate its heat, thereby providing a safe dry heating means for the sauna.
As can be appreciated, because of size and temperature, a high temperature sauna within a spa system has only limited redundancy built into its heating plant. Therefore, when a part fails, the entire spa system often must be shut down. Because of the high temperatures involved, such shutdowns can be lengthy because of the time required for cooling down the oven to a safe temperature, human intervention for repair, and subsequent heat up. Further, present systems also require frequent maintenance, and therefore require periodic shutdowns. It would be preferable to have a system requiring far less maintenance and a system which is significantly less prone to failure.
In the prior art, an oven is heated using a gas-fired combustion burner. The gas-fired burner heats air in a plenum to very high temperatures and a fan is used to direct the heated air through duct work and into the oven, thereby heating the oven and a movable heat source in the oven. The elevated temperatures (typically in excess of 800° F.) necessary to heat the structure are achieved using a gas-fired system, which requires a significant open flame emanating within the combustion burner. Such a system operating at high temperatures and with an open flame and duct work, is conformant to the regulatory codes of some but not all municipalities. Even when permitted, such an open flame presents a significant fire and health hazard. Further, the flame is generated by a burner disposed at a fair distance from the oven, which requires duct work of significant length and complexity. Depending upon the distance from the burner, the duct work may include bends and turns. Standard duct work is prone to leaks, cracking, and heat loss at these high temperatures. The result is that the overall system is not as energy efficient. Further, because the duct work itself transports very hot air, it must be kept in areas away from those people tend to be in. Generally speaking, the duct work requires frequent maintenance because it is operating at much higher temperatures than normal duct work. Moreover, because no such duct work is in use in any other industry, it must be custom made for the particular sauna and is very expensive.
In addition, because of the distance from the combustion chamber of the burner to the oven, a plurality of blade fans is often used in the prior art to force hot gases to the oven. These blade fans are also prone to failure when operating at high temperatures and also require appreciable maintenance because the temperatures typically are far in excess of the normal operating temperatures of such fans.
Further, in the prior art, the heated structure rests on a carriage and the carriage is transported from the oven to the spa using a chain-based system. Typically the carriage is attached to a chain and a motor pulls the chain, thereby moving the structure between the oven and the sauna. The chain-based system also requires frequent maintenance and is prone to failure because of high temperature use, temperature extremes, and structural weight.
In addition, the oven and sauna are separated from each other by a door. In the prior art, the door is latched by four air cylinders. These air cylinders must operate in unison so as to allow the doors to function properly, but the air cylinders also are prone to failure and also require frequent maintenance.
The present invention overcomes these limitations by providing for a system and method for heating a sauna without use of gas-fired burners, duct work, or blade fans. The present invention also overcomes the limitation of chain systems for vehicle transport in high temperature environments.
It is an object of the present invention to provide a method and system for heating a sauna with a system employing a much lower failure rate as compared with the failure rate of systems existing in the prior art and where the need for regular maintenance is significantly reduced from that required in the prior art.
It is also an object of the present invention to provide a method and system for heating a sauna without direct use of a combustion source.
It is also an object of the present invention to provide a method and system for heating a sauna by transporting a heated structure without use of a chain-based drive.
It is also an object of the present invention to provide a method and system for circulating air in an oven without use of blade fans.